Amalgamator for recovery of precious metal



Jan; 11, 1955 A. B. HILL 2,699,257

AMALGAMATOR FOR RECOVERY OF PRECIOUS METAL Filed Dec. 2, 1950 2 Sheets-Sheet 1 45 M 4 15 52 5g 5o 42 4/ 50 52 46 /Z 3 fi 4 5 5 l i r q 29 /a 2 a Q 56 27 36 I 5% INVENTOR. AA/SEL B. HILL was BY A rroz/vsvs Jan. 11, 1955 2,699,257

AMALGAMATOR FOR RECOVERY OF PRECIOUS METAL Filed Dec. 2, 1950 2 Sheets-Sheet 2 INVEN TOR. ANS-L B. HILL United States Patent AMALGAMATOR FOR RECOVERY OF PRECIOUS METAL Ansel B. Hill, Seattle, Wash. Application December 2, 1950, Serial No. 198,883 6 Claims. (Cl. 209-183) This invention relates to an amalgamator for the recovery of gold or other heavier than mercury precious metals. My present invention is an improvement over the invention disclosed in my prior Patent Number 2,134,445.

An object of my present invention is to produce a device for use in connection with mill concentrates or placer sands which device is characterized by the absence of water. More particularly, the device of my present invention provides for a mechanical action forcing the placer sands or mill concentrates upwardly through a mercury bath and to provide a particular action enhancing the aflinity of the precious metal particles to amalgamate with the mercury so that such precious metal particles may be recovered from the mercury.

In describing my invention, reference will be hereinafter made to the recovery of gold from placer sands, but it is to be understood that such is to be taken as an example and not as a limitation of my invention.

Other objects and advantages of the invention will become apparent as the description of the same proceeds and the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of the specification, with the understanding, however, that the invention is not to be limited to the exact details of construction shown and described since obvious modifications will occur to a person skilled in the art.

Figure 1 is a vertical sectional view, with parts shown in elevation, of a device embodying my invention;

Fig. 2 is a detached top plan view of a vibrator mechanism employed in my invention;

Fig. 3 is a detached plan view, with a fragment shown in section, of the lowermost revolving feed disk, said figure being taken substantially on broken line 3-3 of Fig. 1;

Fig. 4 is a detached plan view, partly in section, and taken substantially on broken line 4-4 of Fig. l, and showing another of the revolving feed disks; and

Fig. 5 is a detached plan view, partly in section, and taken substantially on broken line 5-5 of Fig. 1, and showing one of the stationary disks.

Referring now to Fig. 1 of the drawings, a welded steel cylindrical body has a hopper-like bottom 11. The body 10 is provided with a rubber lining 12, and body 10 is filled with mercury such as to the level indicated by 13.

The cylindrical body upper portion 14.

The rubber lining 12 cooperates with electrical apparatus employed in my invention, and further provides greater resistance to abrasion than if the body 10 were not rubber-lined. The enlarged upper portion 14 of the body 10 provides for an enlarged chamber in which my 10 is provided with an enlarged vibrator, shown detached in Fig. 2, may operate as hereinafter described.

Placer sands are delivered into the device down intake spout 15 and are urged downwardly into the bottom of the body 10 by any suitable means, such as a screw flight conveyor 16 driven by any suitable means as is indicated by a pulley 17. The screw flight conveyor 16 is suspendedly supported by bearings 17' by any conventional means (not shown). The flight 18 of the screw flight conveyor 16 may be of any suitable pitch to feed material downwardly below into the lower portion of the body 10 and either single or double flight conveyors may be employed. As the construction for mounting 2,699,257 Patented Jan. 1 1, 1955 and driving the screw flight conveyor 16 may be conventional, parts are diagrammatically shown. The screw flight conveyor 16 rotates within a fixed cylinder 19 which is suspendedly supported by any fixed support 20. The fixed support 20 supports a driven cylindrical member 21 by any suitable non-friction bearings and may be driven by any usual means such as is indicated by the pulley 22. The rotary cylinder 21 supports a plurality of rubber covered steel disk members 23 and 24 shown in Fig. l and also shown detached respectively in Figs. 3 and 4.

Referring now to Fig. 3, each of the disks 23 is composed of a plurality of steel plates 25 which have serrations or saw teeth on their trailing edges. The plates 25 are provided with interfitting rubber coverings 26. A plurality of the disks 23 are provided, such as three, as indicated in Fig. 1 of the drawings, and they are fixedly secured to the cylinder 21 and rotate therewith.

The lower disk 24 has its blades 27 angularly disposed to the vertical as appears in Fig. 1 and each of the blades 27 is provided with a rubber covering 28 and each of the trailing edges of the blades 27 is serrated or saw toothed as indicated. While I have indicated that the disks 23 have more blades than the disks 24, this is not to be considered as a limitation. I find it more convenient to employ blades 27 which are somewhat larger than the blades 26 for strength purposes. However, in both the disks 23 and 24 I preferably have the serrated edges in reasonably close proximity to the lead edge of the next succeeding blade.

Below and in close are stationary disks 5 of the drawings. ing up of material on proximity to each of the disks 23 29 which are shown detached in Fig. Such arrangement prevents buildthe bottom of disks 23. Each of the stationary disks 29 is provided with radial blades or spokes 30 secured to a ring-like portion 31 provided with spaced detent portions 32. To secure each ring 31 to the cylindrical body 10, a plurality of set screws 33 are employed. These set screws 33 are threaded into openings in the body 10 and lock nuts 34 are provided to secure any adjusted portion and thus hold the stationary disks 29 in place. Two of the screws 33 and lock Washers 34 have been sectioned in Fig. 1 of the drawings to show details of construction which may be employed. This construction makes it possible to readily remove the stationary rings 31 as well as other parts. within body 10 when the same is desired. Circular electrodes 35 and 36 are provided and the electrode 35 is near the top and below the mercury level, while electrode 36 is near the bottom of the body 10. The electrode 36 is connected to a positive source of D. C. energy while electrode 35 is connected to the negative pole of said source of electrical energy. The electrodes 35 and 36 are of a size to carry direct current of relatively low voltage and relatively high amperage. In addition to the various rubber linings previously mentioned, a rubber tube 37 is placed about rotary cylinder 21 at the level of the mercury so as to cause flow of electrical energy between the electrodes 36 and 35 and prevent any substantial shunting of electricity via metal parts of the device rather than through the mercury bath.

Liquid chemical feed rings 38 comprises two semicircular members and each has inlets 39 and such rings are located near the bottom of the body 10. Each ring has outlet openings 40. By the use of suitable valves the amount of liquid chemical which is injected into the device may be controlled. Many liquid chemicals are now commonly being used in mercury amalgamators employing two electrodes and hence the type of liquid chemicals to be employed and the amperage and voltage of the D. C. energy are not therefore further disclosed in detail. In a general way, the liquid chemicals employed function to cleanse the mercury.

In the upper portion 14 of the body 10, I employ a vibrator mechanism. This vibrator mechanism is shown detached in plan in Fig. 2 and in side elevation in Fig. 1 and comprises a ring 41 carried by vibrator arms 42. The ring 41 carries a smaller concentric ring 43 by bars 44. The vibrator arms 42 connect to both rings 41 and 43 and in turn have one end portion pivoted to link 45 which link 45 is pivotally mounted by frame structure 46. The

other end portion of the vibrator arms, comprising vibrator arm parts 42 interconnected with each other through rings 41 and 43 as well as bars 44, is connected to an electrical magnetic vibrator 47. The vibrator 47 is of the usual electric type and is connected to any suitable source of power by means not shown. The vibrator is spring loaded as by spring 48 so that it is electrically driven in one way and returns under the influence of spring 48 in the other direction.

A plurality of plate sections forming a star wheel 49 are carried by the ring 41 through depending straps or bars 50. Also, a plurality of plates forming the smaller star wheel 51 are carried by the ring 43 through depending straps or bars 52. Preferably there are two small star wheels 51 and two larger star wheels 49 and the rings 41 and 43, upper star wheels 49, and 51, as well as lower star wheels 49 and 51 are all interconnected through straps 50 and 52.

In the operation of my said device, mill concentrates or sand is fed into the machine through an intake spout diagrammatically illustrated by 15. The machine has been previously filled with mercury to the desired level and the material is forced by mechanical action of the screw flight conveyor 16 downwardly and into the hopper like bottom portion 11 of the body 10. By reason of such screw flight conveyor 16 the material is thrown radially outwardly and then forced upwardly by incoming material and by reason of the differential in weight between the mercury and the mill concentrates. The blades 27 of the disks 24 are preferably inclined upwardly as shown in Fig. 1 of the drawings and they cause the material to rise evenly. The saw toothed or serrated formation on the trailing edges of the blades 27 causes very uniform distribution of the material. As the material rises further in the machine it passes through fixed or stationary disks 29 and immediately thereafter passes through rotating disks 23. This causes eddying currents which continuously separate the material step by step as it ascends through chambers and 14 of the device and thus exposes the gold particles to the mercury an under pressure. Thus I have provided a plurality of stages, such as three, where the material rising through the mercury is subjected to the action of the stationary disks 29 and thereafter immediately subjected to the action of the rotating disks 23. In both instances I have shown the trailing edges of the blades as having serration? thereon. This seems to provide the most desired resu t.

While not essential, it is preferably that the material also be subjected to the action of direct current which passes through the mercury. This tends to cleanse the mercury and speeds up the amalgamation process. Also, preferably the usual chemicals employed in connection with amalgamators may be employed, and delivered into the device via conduits 39 and out Amalgamated concentrates which are heavier than mercury may be discharged from the hopper like bottom 11 via conduit 53 which is fitted with cocks or valves 54 and 55.

As the material rises to the top of the mercury and attempts to overflow the walls of the body portion 14, it is vibrated back and forth by reason of the vibration of the star wheels under influence of vibrator 47 and spring 48. This causes a cleaning of the mercury and the material overflowing and being delivered into discharge chamber 56 is freed of mercury and the loss of mercury is reduced to a minimum.

From the foregoing it will be apparent that I have provided a chamber 10-14 wherein mercury may be disposed and granular precious metal bearing ore may be urged downwardly of tube or cylinder 19 and thence outwardly and upwardly in chamber 1014. In this respect, the disk 24, because of its shape, tends to urge the ore radially of the tube or cylinder 19. As the granular ore rises upwardly in the chamber 1(i-14 it engages a plurality of sets of disks 23 and 29. The disks 23 have a central hub portion and the disks 29 provide a central open portion and together provide a plurality of outwardly and inwardly directed and vertically spaced, flat, and horizontal fins and respectively. Each of the fins 25 and 30 of the disks 23 and 29 have a serrated edge portion and the serrated edge portions of disks 23 are preferably placed on the trailing edge portion of the driven disks 23. Thus there is provided a passageway between the fins of either of the disks 23 and 29 and discharge opening 40. 1

the passageways are bounded by the edge portion of one fin and the serrated edge portion of an adjacent fin. The disks 23 and 29 are horizontally disposed and are preferably alternately driven and stationary. Also, preferably all of the disks are rubber covered to augment their wearing life and to prevent interference between electrical energy traveling between electrodes 36 and 35. As the ore loses its precious metal by being amalgamated with the mercury, the overflowing granular material reaches the vibrating mechanism. This vibrating mechanism constitutes a plurality of ore engaging plates, preferably larger star wheels 49 and smaller star wheels 51, and the plates of these star wheels move transversely of and in the upper portion of the chamber 14. Also, the plates of the star wheels 49 and 51 are angularly positioned relative to the direction of travel of the vibrating mechanism. The star wheels are reciprocated in and transversely of the upper portion of the chamber 14. While the move ment is very slight and is in the order of thousandths of an inch there is a transverse reciprocating motion. This vibratory or reciprocating motion causes the mercury to move downwardly into the main mercury bath and I have found that there is very little loss of mercury due to the said vibratory reciprocating action of the star wheels. While I have shown the vibratory mechanism as comprising conceptive star wheels, obviously other shapes and forms may be employed. There should be a number of plates contacting the overflowing material so that there is sufficient contact between the plates and the overflowing material to provide for uniform agitation or vibrating of the same and thus more uniform results in causing the overflowing material to release mercury being carried therein.

Obviously, changes may be made in the forms, dimensions and arrangement of the parts of my invention without departing from the principle thereof, the above setting forth only preferred forms of embodiment.

I claim:

1. An amalgamator comprising a chamber wherein mercury may be disposed and granular precious metal bearmg ore may be urged upwardly through said chamber; a plurality of ore-engaging plates mounted for reciprocating movement transversely of and in the upper portion of said chamber and adjacent the overflow level thereof, said plates being disposed to form a star wheel; electrically driven reciprocating means connected with said plates and urging the same in one direction; and spring means urging said plates in the opposite direction, whereby material before overflowing the said chamber is agitated by said ore-engaging plates to clean the same of its mercury.

2. An amalgamator comprising a chamber wherein mercury may be disposed and granular precious metal bearing ore may be urged upwardly through said chamher; a plurality of ore-engaging plates mounted for reciprocating movement transversely of and in the upper portion of said chamber and adjacent the overflow level thereof, said plates being disposed to form two star wheels, one within the other; electrically driven reciprocating means connected with said plates and urging the same in one direction; and spring means urging said plates in the opposite direction, whereby material before overflowing the said chamber is agitated by said oreengaging plates to clean the same of its mercury.

3. An amalgamator comprising a chamber wherein mercury may be disposed and granular precious metal bearing ore may be urged upwardly through said chamber; a plurality of horizontally disposed, alternately driven and stationary disks having passageways through which said ore may pass, each of said disks having a hub portion and a plurality of outwardly directed and spaced flat fins, the said driven disks having trailing serrated edge portions, the said passageways through the driven disks constituting the spaces between two adjacent fins and being bounded by the leading edge portion of one fin and the serrated trailing edge portion of an adjacent fin; and means urging ore upwardly in said chamber and through the passageways in said disks.

4. An amalgamator comprising a chamber wherein mercury may be disposed and granular precious metal bearmg ore may be urged upwardly through said chamber; a plurality of horizontally disposed driven disks having passageways through which said ore may pass, each of said d sks having a hub portion and a plurality of outwardly directed and spaced flat fins having serrated trailing edge portions, the said passageways constituting the spaces between fins and being bounded by the edge portion of one fin and the errated edge portion of an adjacent fin; and means urging ore upwardly in said chamber and through the passageways in said disks.

5. An amalgamator comprising a chamber wherein mercury may be disposed and granular precious metal bearing ore may be urged upwardly through said chamber; a plurality of horizontally disposed, rubber covered, driven disks having passageways through which said ore may pass, each of said disks having a hub portion and a plurality of outwardly directed and spaced flat fins having serrated trailing edge portions, the said passageways constituting the spaces between fins and being bounded by the edge portion of one fin and the serrated edge portion of an adjacent fin; and means urging ore upwardly in said chamber and through the passageways in said disks.

6. An amalgamator comprising a rubber lined chamber wherein mercury may be disposed and granular precious metal bearing ore may be urged upwardly through said chamber; a plurality of horizontal, rubber covered disks having passageways through which said ore may pass,

each of said disks having a hub portion and a plurality of outwardly directed and spaced flat fins, the said passageways constituting the spaces between fins and being ounded by the edge portion of one fin and the edge portion of an adjacent fin; means urging ore upwardly in said chamber and through the passageways in said disks; and positive and negative electrode means disposed respectively in the bottom and top portions of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 

